in Yemen stop attacking international ships# in the Red Sea.

The U.S. military says ther have been more than two dozen attacks in the# last seven weeks, the most serious yesterday,## when Houthis fired more than 20 drones and# missiles right at U.S. and allied warships.

Nick Schifrin looks at the Houthi# escalation and U.S. options.

NICK SCHIFRIN: In the middle of the Red Sea,# British sailors shoot down incoming Houthi## drones and missiles.

The U.K. and U.S. called# it the Houthis' largest and most com Secretary of State Antony Blinken: ANTONY BLINKEN, U.S. Secretary of# as they did yesterday, there will b NICK SCHIFRIN: British# Defense Minister Grant Shapps: GRANT SHAPPS, British Defense Minister: And we# a major ability to move goods around the world is## being cut off by terrorists and# thugs, and we therefore must act.

NICK SCHIFRIN: Since mid-November, Houthi rebels# have targeted, seized international vessels and## kidnapped foreign sailors.

The Houthis have# said they target ships linked to Israel,## but, today, a Houthi spokesman said# the target was an American warship,## retribution for the U.S. Navy last month sinking# Houthi boats and killing 10 Houthi f YAHYA SAREA, Houthi Military Spokesman# (through translator): The Yemeni Houthi## armed forces affirm hostile threats within the legitimate right# to defend our country, people and nation.

NICK SCHIFRIN: Some 15 percent of world# shipping goes through the Suez Canal,## which links the Red Sea with the Mediterranean.# Houthi attacks have so far co mmerce, forcing shippers to reroute their# vessels and increasing shipping costs.

Last month, the U.S. launched a multinational# coalition to protect commercial shipping.

And,## last week, the U.S. and 13 other countries issued# what an official called a final warning.

"The## Houthis will bear the responsibility of the# consequences should they continue to threaten## lives, the global economy and the free flow of# commerce in the region's critical waterways."

But, so far, the U.S. has not# followed through on that threat.

JOHN KIRBY, NSC Coordinator For# Strategic Communications: The best## solution to th NICK SCHIFRIN: The Houthis are a rebel group# backed by Iran that in 2014 seized the Yemeni## capital, Sanaa.

For years, they fought Saudi# Arabia as part of a brutal civil war that## killed hundreds of thousands, but, for 20# months, there's been a shaky cease-fire.

Houthi missiles are based on Iranian# technology, and a U.S. official tells "PBS## NewsHour" Iran is coordinating the current# attacks and helping provide the targets.

MAN: The draft resolution is adopted.

NICK SCHIFRIN: In New York today, the# U.N. Security Council passed demanding the Houthis cease all attacks# and release two dozen fo BARBARA WOODWARD, British Ambassador to the# United Nations: We will not stand by and allow## the Houthis to threaten civilian vessels and# hold globa NICK SCHIFRIN: So what is motivating the Houthis## to launch these attacks an For that, we turn to Jonathan Panikoff,## the director of the Scowcroft Middle# Co uncil and the former deputy national# intelligence officer for the Jonathan Panikoff, thank you very# much.

Welcome to the "NewsHour."

What do the Houthis gain# by launching these attacks?

JONATHAN PANIKOFF, Atlantic Council:# Thank you so much for having me.

I think the Houthis really is the way I would frame it.

The Houthis don't# have access to Yemen's energy resources.

The Houthis are trying to negotiate a final resolution# in terms of the long-running conflict with Saudi## Arabia.

I think it's provided them, I think,# greater leverage probably in those negotiations.

And so I think the Houthis see this as a# realistic policy option in order to try## and better their position for the long# term in Yemen for the years to come.

NICK SCHIFRIN: But do they also risk# something by continuing these attacks,## especially after they came out today and said# explicitly that the target was JO NATHAN PANIKOFF: Certainly, they could.

Obviously, the United St Sea.

It's had multiple countries join, though,# importantly, not some of the Gulf countries,## like Saudi Arabia and the Emiratis, who# have long been in conflict with the Houthis.

So it's possible, obviously, the U.S. will# respond.

And we saw some discussion today## and references that the U.S. and its# allies are considering doing so.

But## the Houthis have been having a war for# years now.

I'm skeptical that a response,## especially a one-time response or even# two-time response, is necessarily going## to deter them if they think that's really going# to better their position in the NI CK SCHIFRIN: The U.S. last week gave what a# U.S. official called a final warning.

And you## heard earlier today John Kirby from the# National Security Council there clearly## sending the message that still they# hope the Houthis stop these attacks.

Bottom line, do you think the U.S.# should launch a military strike?

JONATHAN PANIKOFF: I think a military strike is## probably going to be nec It's not that I think a military strike is# necessarily likely to stop the Houthis from## continuing their attacks, but not having the# deterrence that the U.S. needs by refusing## to respond or declining to respond also# signals to other actors in the region,## other Iranian-backed proxies# that they too may have a level## of freedom to engage in attacks against# U.S. forces, whether in Iraq or in S or that Hezbollah may be able to actually push# the boundaries in Lebanon and into Israel.

The U.S. has said very clearly that's its# number one goal, is to avoid a regional## conflict.

I think not responding at this point# risks deterrence not being taken seriously by## our adversaries and actually bringing about# the very conflict the U.S. is trying to avoid.

NICK SCHIFRIN: The other argument that I hear# from experts who I spoke to today is that, look,## a military strike would open up another front,# which is a bad idea, and that any weapons or## any capabilities of the Houthis that the U.S.# destroyed would quickly be refilled by Iran.

What's your response to that?

JONATHAN PANIKOFF: I thi I think whether it opened up another front# assumes that the front hasn't already opened.## I think we have seen 26 Houthi attacks# since the 19th of November.

We're seeing## 15 percent of all maritime commerce goes# through the Red Sea.

And you're starting to## see huge amounts now having to go around# at big cost to companies and countries.

I think we're already really quite# on the precipice of being there,## of having another front to open.

I actually# worry much more that not responding now,## as we haven't in a meaningful# way for about a month-and-a-half,## has clearly been a strategy that# hasn't worked.

If we don't respond now,## I actually think it increases the chance that we# end up in a regional conflict, NI CK SCHIFRIN: In some ways, could Saudi Arabia# actually want the United States to launch this## military strike, to degrade Houthi capabilities,# and then to come in afterward and say, oh,## we're the peacemaker, we're going to# continue these talks with the Houthis?

JONATHAN PANIKOFF: I think the Saudis are# certainly supportive of the mili if the U.S. is successful in them.# And that really means that the U.S.## actually manages to be successful# in having some level of deterrence.

The flip side of that is that if the U.S. says# we're going to do one strike or two strikes,## but not actually keep the pressure on, then# my guess is the Saudis are going to be pretty## annoyed and feel like it didn't actually do much,# because you didn't stay engaged in the conflict.

NICK SCHIFRIN: And, finally,# let's talk about Iranian support.

The National Security Council spok saying that Iran was -- quote -- "deeply# involved in planning the operations against## commercial vessels" and was -- quote -- "providing# tactical intelligence on that vessel's locations."

How does that work?

JONATHAN PANIK its various partners and proxies throughout# the region, and that includes the Houthis.

In this case, it means that the Iranians# may have identified targets that they have## passed to the Houthis.

It could mean that# the Iranians have certain targets that they## have known for years they have wanted Houthis# to strike, or it could mean that the Houthis## identified targets and went to the Iranians to# validate them, to say, does this make sense?

So, I think there's a variety of ways that# that can work, but the bottom line is, one way## or the other, Iranian support for the Houthis is# helping them to take these strikes successfully.

NICK SCHIFRIN: Jonathan Panikoff for the# Atlantic Council, thank you very much.

JONATHAN PANIKOFF: Thank you.